Rotary engine



Patented Aug. 9, I898.

M. F. DEAN &. T. MCCOY.

ROTARY ENGINE.

(Application filed Aug. 24. 1897..)

2 Sheets-Sheet I.

(No Model.)

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Patented Aug. 9, I898.

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MILLARD F. DEAN AND TAYLOR MCCOY, OF POCA, 'EST VIRGINIA.

ROTARY ENGINE.

SPECIFICATION forming'part of Letters Patent No. 608,762, dated August 9, 1898. Application filed August 24,1897. Serial No. 649,324. (NomodcL) To all whom it may concern.-

130 it known that we, MILLARD F. DEAN and TAYLOR MCCOY, citizens of theUnited States of America, residing at Poca, in the county of Putnam and State of West Virginia, have invented certain new and useful Improvements in Rotary Engines; and we do hereby declare the following to be a full, clear, and exact de scription of the invention, such as will enable others skilledin the art to which itappertains to make and use the same.

Our invention relates to novel and useful improvements in steam-engines of that class commonly known as rotary engines; and it has for its object, primarily, to provide a simple and comparatively inexpensive engine embodying such a construction that the steam will be economically used and. the power thereof utilized to the fullest extent.

A further object is to improve the construction of the valves and the means for operatin g them, whereby the steam can be admitted to the cylinder to operate upon the piston directly from the steam-chest during the entire stroke of the piston or admitted to said piston for a part of the stroke only to rotate the same by the expansion of the steam for the remainder of the revolution or stroke thereof.

lVith these and other objects in view, that will become apparent in the course of the following description, all looking toward simplifying and improving engines of this character generally, our invention consists in the novel combination and arrangement of parts, that will hereinafter be fully described, and the points of novelty will be particularly pointed out in the appended claims.

To accomplish the ends above suggested, we have devised the engine illustrated in the accompanying drawings, in which Figure lis a side elevation. Fig. 2 isa longitudinal section taken a little to one side of the center of the engine. Fig. 3 is a detail perspective view of one of the valves used in carrying out the invention. Fig. at is a trans verse central section showing the manner of duplicating the valve-operating mechanism in an engine adapted to be reversed. Fig. 5 is a detailside elevation of a cam forming a portion of the mechanism for operating the valves controlling the admission of steam to the cylinder. Fig. 6 shows the same parts as Fig. 5 as they appear u ndcr difl" erent adj ustment. Fig. 7 is a longitudinal section of the cam devices.

Referring to the drawings, throughout which like figures and letters of reference indicate like parts, the numeral 1 designates the cylinder, which in the present instance is open at both ends to enable the engine to be more lightly constructed and to give free access to the piston to repair the same and for other purposes, that will presently become apparent. The cylinder is cast with flanges on opposite sides thereof a little below the center, as indicated by the numeral 2, which flanges are adapted to rest upon the sides of a suitable .passing from one side of the piston to the other. Bolted or otherwise secured to the outer periphery of the piston are two pistonwings 10, which wings,"it will be apparent by reference to Fig. i, are oppositely disposed and at oppposite ends of the piston in the spaces between the central and end flanges. Said piston-wings, as clearly shown, are hollow and adapted to receive oil, which is fed to the packing-strips 11 in recesses 12, extending longitudinally throughout the length of the piston-wing, and thereby to the inner periphery of the cylinder. As a means for filling the piston-wings pipes 13 are provided, to which ready access can be had from the ends of the cylinder.

The numeral 14: indicates the inlet-ports, through which steam is admitted from a steam-chest 15, divided by a central partition 15, forming compartments, each of which contains a slide-valve 16 with perforations the'rethrough adapted to establish communication between the cylinder and the steamchest or to cut off such communication, as the case may be. Each slide-valve extends nearly across the floor of its compartment of the steam-chest, and two rods 17 are aflixed to the valves, respectively, and connected outside the steam-chest by a crossbar 18, said rods extending through suitable stuffingboxes on the steam-chest. The bar 18 is pivotally connected with an operating-lever 20 by a link 18, and it will be seen that by shifting this lever communication may be established between the steam-chest and either of the two sets of inlet-ports 14, according to which set of ports in the valve are caused to register with such inlet-ports. By this means the direction of rotation of the piston is controlled.

Above the steam-chest 15 there is a cap of generally semicylindrical form, and between which and the upper side of the steamchest there are formed chambers to contain valves 48, in the form of cylinders with end trunnions jo'urnaling in the ends of the chambers. These valves rest over elongated ports 15 in the upper side of the compartmentsof the steam-chest and are themselves provided with elongated ports 48, adapted to register with said ports 15 to establish communication between the interior of the valves and the steam-chest. Opposite said valve-ports 43" there are ports 48", of corresponding area, and a web 51, arched in cross-section, lies over the upper sides of the valves, constituting an abutment for steam having access to it through the said ports 48 for the purpose of balancing the valves. Each valve is also formed in opposite sides with elongated ports 48, of less combined area than the ports 48 and adapted to establish communication be tween the chambers and the interior of the valves. A steam-supply pipe 49 communicates with both of said chambers.

At the lower or inner end of each inlet-port there is pivotally secured an inwardly-openin g flap-valve 21, having its free edge slightly turned up, as indicated at 22. Said valves normally occupy recesses 23, being held therebetween the latter.

in by spiral springs 24, whose inner ends are connected with eyes upon the upper sides of said valves and whose outer ends are connected with set-screws 25, whereby the tension of the springs can be varied, and it will be noted that when the inlet-port back of one of these valves is opened the incoming steam will cause the valve to rock to the position shown at the right-hand side of Fig. 2 against the tension of the spring 24, thus permitting the steam to enter the cylinder freely behind the piston-wing to cause the piston to rotate, the valve constituting a stationary abutment for the steam. There being four inlet ports or passages 14, there are four of these valves, and each one is made to closely engage the side walls of its recess 23, the sides of the flanges 7 and 8, an d the bottom of the channel For this purpose the Valve is preferably constructed as shown in Fig. 3, the same consisting of a piece of metal bent double, with a tubular portion to receive a pivot-rod and a space between for lubricating material, the rod being preferably in the form of a perforated tube, so as to act as a duct for supplying lubricant. The space between the doubled-over portions of the valve is closed in by strips of felt or other suitable material, (indicated at 22%) which strips are clamped between the doubled-over metal portions of the valve and have intimate contact with the before-mentioned surface between which the valve works.

The numeral 38 designates exhaust-ports located centrally between the inlet-ports and communicating, respectively, with pipes 37, which extend across the ends of the cylindercap and are utilized as supports in a manner hereinafter explained.

The cut-off-valve mechanism is of the following description: Keyed to the main shaft just inside the bearing-blocks are eccentrics 26, having eccentric-collars 27 thereon, connected to the upper ends of vertical arms 28, which have their lower ends pivotally connected with slides 29, adapted to slide in recesses 30 in members 31., secured to the in- I ner sides of the base. Secured also to the slides 29 by pivotal connections are the lower ends of double yokes 32, having their upper ends pivotally secured to slides 33, adapted to reciprocate in recesses 34 in plates 35, pivotally hung upon bosses 30, formed upon the exhaust-pipes 37. Secured to the exhaustpipes are keepers 39, constituting guides for reciprocating rods 40, which have their front ends secured to slides 41 on the exhaust-pipe and guided by recesses 42 therein. Connected with the slides 41 by links 43 are levers 44, pivotally secured at or about their centers to fixed arms 45, extending laterally from the steam-chest, and the upper ends of said levers 44 are pivotally connected with the outer ends of arms or links 46, whose inner ends are pivotally connected with rocker-arms 47, rigidly secured to the ends of the hollow valves 48, which are independently'journaled in suitable bearings above the steam-chest. Said valves,it will be noted by reference to Fig. 2, are adapted to be rocked to admit the steam from the inletpipe 49 to the steam-chest. Cams 54 are affixed to the slides 33, respectively, each of said cams comprising two members placed face to face and secured together, with interposed blocks at the ends to afford a space for the rod 40 to pass through, said rod adapted to be reciprocated by the cam and being provided for this purpose with rollers 53 on opposite sides and occupying the substantially diamond-shaped recesses in the confronting faces of the members of the cam. Within each of these recesses there is arranged a switch 55, which is pivoted to the base of the recess and is of substantially the same general outline as the latter. A flat spring 56, fastened at one end to a pin set in one end of a recess 57 in the base of the cam-recess, bears near its outer end against a projection on the switch, and thereby presses the lower end of the latter against one wall of the camrecess.

It will be remembered that the slides 33 are connected with the main shaft and caused to reciprocate thereby, and it will readily be understood that the accompanying vertical rcciprocations of the cams will result in horizontal reeiprocations of the rods 40 by the coaction of the sides of the recesses of said cams and the switch-pieces 55 with the rollers on said rods. lo be more specific, it may be explained that upon downward movement of the cams the outwardly-rounded edges a of the switch-pieces first encounter the rollers on the rods, after which the said rollers are encountered by those portions of the sides of the cam-recesses designated by the letter Z) in Fig. 5, and as the downward movement of the slides continues the upper ends of the switch-pieces are displaced by coming against the rod-rollers, and when said switch-pieces have passed said rollers their springs 56 restore them to initial position, so that when the slides begin to move upwardly the switchpieces pass in contact with the rollers on their sides toward the sides of the recesses encountered in the downward movement of the slides. Then the continued upward movement of the slides brings the portions of the sides of the cam-recesses designated by the letter 0 into engagement with the rollers, and at the conclusion of the upward movement of the slides the position of the rollers in the recesses of the cams is the same as at the beginning of the downward movement. In such restoration of parts to their normal relations the lower ends of the switch-pieces are displaced by their encountering the rollers, and when the upward movement ceases said switches have passed the rollers and are again in normal position, so that upon the ensuing downward movement of the slides the rounded edges CL of the switches will encounter the rollers.

It will be remembered that the rods 40 are in operative connection, respectively, with the rocking valves 48, and hence the reciprocations of said rods resulting from the coaction of their rollers with the sides of the camrecesses and the switches has the effect of moving said valves, and thereby controlling the admission of steam. It will also be remembered that the cam-carrying slides are given a complete reciprocation with each complete revolution of the main shaft, and hence in the course of such revolution of the main shaft each rocking valve is moved from a certain normal position and back again. Now it is evident that the relation of the sides of the cam-recesses and the edges of the switches in the latter to the rollers on the rods controls the movements of the valves. Hence by adjustment of the cams the movements of the valves can be so varied asto apportion the period of admission to the load on the engine.

As hereinbefore explained, the guides for the slides 33, which carry the cams, are pivotally mounted, and it is here to be remarked that the pivots of these slide-guides coincide with the axes of the rollers 53, so that movement of the guides on their pivots does not in any case change the normal position of the rollers hereinbefore described, and it follows that whatever may be the position of the slideguides on their pivots at the upward movement of the slides the valves are always brought to the same position and steam is always admitted at the same point, just as the piston-wing arrives at a position to take steam most effectively. hen a slide 33 is at the limit of its upward movement, the corresponding piston-wing occupies a central position between the two inlet-ports and the valve has sufficient lap to permit the pistonwing to move to the proper position beyond the flap-valve abutment before steam is ad mitted.

The period of admission of steam is determined by the adjustment of the pivotal guides 35. It will be seen that the more these guides are tilted to the left as the parts appear in Figs. 1 and 5 the sooner will the cut-off take place by reason of the upper portion of the right-hand-side of the cam -recess acting against the roller on the rod, whereas the more the guides are tilted to the right the later willthe cut-off take place.

L In the most extreme adjustment of the cam to the right, as illustrated inFig. 6, steam will be admitted through seven-eighths of the revolution, the valve not being completely closed until the rod-roller is engaged with the lower portion of the left-hand edge of the switch in the downward movement of the slide. WVhen the cam is adjusted to the extreme position to the left, steam is admitted through but five-sixteenths of the revolution, for the upper portion of the right-hand side of the cam-recess acts to close the valve in The above are the preferred extremes of adjustment, and of course anyintermediate adj ust-.

the upward movement of the slide.

ment can be had. The adjusting means here shown comprise links 62, pivotally connected l with the guides 35, respectively, and with hand-levers 61, which are pivoted to fixed projections 60 on the cylinder, a segmental rack and a trip-latch being associated with each of said levers.

A It is to be understood that the two pistonwings are located diametrically opposite each other, and hence the eccentrics 26 are set op positely, and when one slide 33 is up the other is down. Hence steam acts alternately against the pistonwvings and a dead-center is impos sible.

Having thus described the mechanism. wherein our invention lies and certain specific operations, we will nowproceed to descriheits operation generally, attention being particularly called to Fig. 2. It will be noted by'reference to this figure that the rocker-valve at ICO IIO

one side of the cylinder is open, admitting a i full head of steam from the inlet-pipe to the steam-chest, and the slide-valve in the steamchest being open to one of the inlet-ports 14 will permit the steam to pass through said port, where it is brought in contact with the top of the valve 21, causing the same to be depressed against the tension of the spring 24. At this point the piston-Wing upon that portion of the piston under the particular valve isin position to take steam, which will cause the piston to revolve until the wing thereon passes the exhaust-port, when the steam which has just acted upon the piston will pass therethrough to the open air. The amount of steam to be admitted to the piston as above mentioned is governed by thevalve mechanism operated by the eccentric upon the shaft, and when it is desired to admit steam to the piston during a portion of its revolution the levers 61 are rocked, causing the members 35, containing the slides 33, to be moved in one direction or the other out of vertical position when said levers are locked, causing the reciprocating rods 40 to so actuate the valves that the steam will be admitted to the cylinder at desired intervals.

It will be understood that the valve-operating mechanisms will be set with such relation to each other that steam will at all times be operating upon one or the other of the pistonwings, and, as has already been stated, the time of admission of steam may be so regulated that steam Will be admitted to one of the piston-wings throughout substantially the entire revolution of the piston and to the other for a portion of the revolution only, or, if found desirable, the valve mechanism can be set to admit steam to both wings upon the piston throughout the entire revolution thereof. When it is desired to reverse the engine, it is obviously only necessary to rock the lever 20, causing the slide-valves to move to the opposite side of the steam-chest, closing one set of ports and opening the other.

It is obvious that the invention herein set forth is susceptible to many changes and modifications involving mechanical skill which may be made within the scope of the invention without departing from the spirit thereof. We do not, therefore, desire to be understood as limiting ourselves to the precise construction of the parts shown in the drawings.

Having thus fully described our invention, what we claim as new, and desire to secure by Letters Patent of the United States, is

' 1. I11 a steam-engine, variable cut-off-valve mechanism comprising a reciprocatory rod operatively connected with the steam-inlet valve, and a reciprocatory endless cam and automatic switch in engagement with said rod and adapted to produce reciprocations thereof substantially at right angles to the reciprocations of the cam and switch, thelatter parts being operatively connected with the piston of the engine for reciprocation thereby and the cam with its switch being adjustable in the plane of reciprocation of the rod to vary the movements thereof and consequently of the valve, substantially as described.

2. In a steam-engine, variable cut-off-valve mechanism comprising a reciprocatory rod operatively connected with the steam-inlet valve, a reciprocatory cam engaged therewith, its acting face being substantially diamondshaped in generaloutline,and a spring-pressed pivotal switch in the cam, the latter together with said switch being adjustable to different degrees of an gnlarity to vary the period of admission of steam, substantially as described.

In a steam engine, a variable cut offvalve mechanism comprising a reciprocatory rod operatively connected with the steam-inlet valve of the engine, an endless cam engaged with said rod, an automatic switch in said cam, and a sliding support for said cam operatively connected with the piston of the engine, with provision for angular adjustment determining the period of admission of steam, substantially as described.

4. In a steam-engine, variable cut-oftvalve mechanism comprising a reciprocatory rod operatively connected with the steam-inlet valve, and a reciprocatory endless cam and automatic switch in engagement with said rod and adapted to produce reciprocations thereof substantially-at right angles to the reciprocations of the cam and switch, the latter parts being operatively connected with the piston of the engine for reciprocation thereby and the cam with its switch being adjustable in the plane of reciprocation of the rod to vary the movements thereof and consequently of the valve, their center of movement in such adjustment coinciding with the point of engagement of the rod with the cam when the latter is at the end of its movement in one direction.

5. In a steam-engine, a variable cut-olfvalve mechanism comprising a reciprocatory roller-equipped rod operatively connected with the steam-inlet valve, a camway embracing the roller on said rod, a pivotal spring.

actuated switch in said camway, and a reciprocatory support for the latter operatively connected with the piston of the engine with provision for-adjustment about a pivot coincident with the axis of the rod-roller when the support is at the end of its movement in one direction, substantially as and for the purpose described.

6. In a steam-engine, a variable cut-olfvalve mechanism comprising a reciprocating rod operatively connected with the steam-i11- let valve, a pivoted guideway, means for setting the same at different adjustments, a slide in said guideway and operatively connected with the piston, and a camway and switch on the slide and engaging the rod, substantially as and for the purpose described.

7. In a rotary steam-engine, the combination of a'cylinder having inlet and exhaust ports, a piston shell having a peripheral specification in the presence of two subscribin g witnesses.

,MILLARD F. DEAN.

TAYLOR MCCOY.

Witnesses:

S. P. COURTNEY, E. B. NEAL. 

